Sounding signal for object detection in a radar system

ABSTRACT

Examples disclosed herein relate to an antenna system in a radar system for object detection with a sounding signal. The antenna system includes a radiating array of elements configured to transmit a reference signal and an antenna controller coupled to the radiating array of elements. The antenna controller is configured to detect a set of reflections of the reference signal from an object. The antenna is configured to determine a location of the object and a mobility status from the set of reflections. The antenna controller is also configured to generate signaling indicating the location and mobility status of the object as output to identify a target object different from the object. Other examples disclosed herein relate to a radar system and a method of object detection with the radar system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Non-Provisional ApplicationNo. 16/542,851, filed on Aug. 16, 2019, and incorporated by reference inits entirety; and claims priority from U.S. Provisional Application No.62/765,178, filed on Aug. 17, 2018, and incorporated by reference in itsentirety.

BACKGROUND

Wireless communications are used in an ever-expanding range of productswith efficiency requirements. In a wireless transmission system, such asradar or cellular communications, the size of the antenna is determinedby the transmission characteristics. With the widespread application ofwireless applications, the footprint and other parameters allocated fora given antenna, or radiating structure, are constrained. In addition,the demands on the capabilities of the antenna continue to increase,such as, among others, increased bandwidth, finer control, and increasedrange. In these applications, there is a desire to reduce the powerconsumption, spatial footprint and computing power for operation of theantenna and transmission structure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application may be more fully appreciated in connection withthe following detailed description taken in conjunction with theaccompanying drawings, which are not drawn to scale and in which likereference characters refer to like parts throughout, and wherein:

FIG. 1 illustrates an environment having a vehicle with a radar system,according to various implementations of the subject technology;

FIGS. 2-6 illustrate operation of a radar system as in FIG. 1 ,according to various implementations of the subject technology;

FIG. 7 illustrates a process for operating a radar system, according tovarious implementations of the subject technology;

FIGS. 8 and 9 illustrate an environment having a vehicle with a radarsystem, according to various implementations of the subject technology;

FIG. 10 illustrates a process for determining an environmental profile,according to various implementations of the subject technology;

FIG. 11 illustrates a transceiver module, according to variousimplementations of the subject technology; and

FIG. 12 illustrates an antenna module within the transceiver module ofFIG. 11 , according to various implementations of the subjecttechnology.

DETAILED DESCRIPTION

The present disclosure provides wireless systems and radar systems whereinformation is transmitted via electromagnetic waves for communicationand object detection. In current systems the various scanning scenarioshave very tight timing requirements, which impact the scan range, thepost-processing, and the control of the antenna(s). The speed and datathroughput for applications such as autonomous vehicles and 5Gcommunications and their future developments demand microsecondresponses, and these requirements will reduce dramatically withexpansion of these use cases.

For example, in an autonomous vehicle a main controller, or sensorfusion, is used to receive multiple type signals and information andthen determine a next state and action for the vehicle. The sensorfusion is designed to capture data on a fast-moving vehicle. The presentdisclosure provides methods and apparatuses to receive this informationand generate an understanding of the environment, and in someapplications may be used to produce a three-dimensional (3D) point cloudrepresentation. Radar is used to identify object locations andvelocities, and may be used to identify acceleration, reflectivity andother characteristics. The present disclosure identifies stationaryobstacles in an environment and builds a landscape that the sensorfusion may track against as the vehicle moves, reducing the processingtime and taking advantage of non-line of sight capacities available inthese methods and apparatuses.

The information received gives an instantaneous reconstruction of themoving obstacles and infrastructure. In some applications, the sensorfusion accesses global positioning information, such as GlobalPositioning System (GPS) information, and uses this information to guidea vehicle. This instantaneous information is critical in autonomousvehicles for safe operation.

The present disclosure provides for signaling, such as a soundingsignal, to locate and discriminate stationary objects from mobileobjects. This is similar to the sounding signal in a cellular system,where the system obtains channel information to set up and maintain acall from a transmission point to multiple antennas; in the presentdisclosure, and claims depending thereon.

In some implementations, a radar system steers a highly-directive RadioFrequency (RF) beam that serves as the sounding signal and canaccurately determine the location and speed of road objects. The subjecttechnology is not prohibited by weather conditions or clutter in anenvironment. The subject technology uses radar to provide informationfor two-dimensional (2D) image capability as they measure range andazimuth angle, providing distance to an object and azimuth angleidentifying a projected location on a horizontal plane, respectively,without the use of traditional large antenna elements.

The subject technology is applicable in wireless communication and radarapplications, and in particular those incorporating meta-structurescapable of manipulating electromagnetic waves using engineered radiatingstructures. For example, the present disclosure provides for antennastructures having meta-structure elements and arrays. A meta-structure(MTS), as generally defined herein, is an engineered, non- orsemi-periodic structure that is spatially distributed to meet a specificphase and frequency distribution. In some implementations, themeta-structures include metamaterials such as metamaterial cells orelements. There are structures and configurations within a feed networkto the metamaterial elements that increase performance of the antennastructures in many applications, including vehicular radar modules.Additionally, the present disclosures provide methods and apparatusesfor generating wireless signals, such as radar signals having improveddirectivity and reduced undesired radiation patterns aspects, such asside lobes. The present disclosure provides antennas with unprecedentedcapability of generating RF waves for radar systems. The presentdisclosure provides improved sensor capability and support autonomousdriving by providing one of the sensors used for object detection. Thepresent disclosure is not limited to these applications and may bereadily employed in other antenna applications, such as wirelesscommunications, 5G cellular, fixed wireless and so forth.

The subject technology relates to smart active antennas withunprecedented capability of manipulating RF waves to scan an entireenvironment in a fraction of the time of current systems. The subjecttechnology also relates to smart beam steering and beam forming usingMTS radiating structures in a variety of configurations, in whichelectrical changes to the antenna are used to achieve phase shifting andadjustment reducing the complexity and processing time and enabling fastscans of up to approximately 360° field of view for long range objectdetection.

The present disclosure provides for methods and apparatuses forradiating structures, such as for radar and cellular antennas, andprovides enhanced phase shifting of the transmitted signal to achievetransmission in the autonomous vehicle communication and detectionspectrum, which in the US is approximately 77 GHz and has a 5 GHz range,specifically, 76 GHz to 81 GHz, to reduce the computational complexityof the system, and to increase the transmission speed. The presentdisclosure accomplishes these goals by taking advantage of theproperties of hexagonal structures coupled with novel feed structures.In some implementations, the present disclosure accomplishes these goalsby taking advantage of the properties of MTS elements coupled with novelfeed structures.

The subject technology supports autonomous driving with improved sensorperformance, all-weather/all-condition detection, advanceddecision-making algorithms and interaction with other sensors throughsensor fusion. These configurations optimize the use of radar sensors,as radar is not inhibited by weather conditions in many applications,such as for self-driving cars. The ability to capture environmentalinformation early aids control of a vehicle, allowing anticipation ofhazards and changing conditions. The sensor performance is also enhancedwith these structures, enabling long-range and short-range visibility tothe controller. In an automotive application, short-range is consideredwithin 30 meters of a vehicle, such as to detect a person in a crosswalk directly in front of the vehicle; and long-range is considered tobe 250 meters or more, such as to detect approaching cars on a highway.The present disclosure provides for automotive radar sensors capable ofreconstructing the world around them and are effectively a radar“digital eye,” having true 3D vision and capable of human-likeinterpretation of the world.

The detailed description set forth below is intended as a description ofvarious configurations of the subject technology and is not intended torepresent the only configurations in which the subject technology may bepracticed. The appended drawings are incorporated herein and constitutea part of the detailed description. The detailed description includesspecific details for the purpose of providing a thorough understandingof the subject technology. However, the subject technology is notlimited to the specific details set forth herein and may be practicedusing one or more implementations. In one or more instances, structuresand components are shown in block diagram form in order to avoidobscuring the concepts of the subject technology. In other instances,well-known methods and structures may not be described in detail toavoid unnecessarily obscuring the description of the examples. Also, theexamples may be used in combination with each other.

FIG. 1 conceptually illustrates a radar system 20, according to variousimplementations of the subject technology. In an example implementationillustrated in FIG. 1 , an environment 100 is a roadway with movingvehicles and stationary objects. The vehicle 110 includes the radarsystem 20 positioned to detect objects in its path in environment 100.There are several objects positioned therein, including a parked policecar 120 on the opposite side of the road, a road sign 140, and abillboard 130. There is also another vehicle 150 approaching vehicle110. The environment includes some stationary objects, such as a tree142 and a traffic sign 140. The billboard 130 may be a stationarystructure or may be a mobile structure. Similarly, the police vehicle120 is stopped and may be considered a stationary object for the timeperiod of interest, specifically, while the car moves from point A topoint B. While there may be various target objects, those in the path ofthe vehicle 110 are the targets of interests, referred to herein as“targets.”

In identifying targets an ideal system will distinguish targets fromnon-targets, referred to herein as “clutter.” Clutter includes objectsthat are not in the direct path, or anticipated path, of the vehicle,such as self-interference, jamming interference, objects, buildings,structures, and so forth. Self-interference includes signals thatoriginate with radar system 20 and then are reflected or bounce off ofobjects. When a radar beam is transmitted over the air, the strength orgain of the signal at interaction, the angle at which the signalarrives, the reflectivity of the object, the shape of the object, andother parameters are useful for differentiating between targets andnon-targets. When there are many objects in the environment, the radarsystem 20 detects each one's location and velocity. In someimplementations, a specific transmission signal, such as a FrequencyModulated Continuous Wave (FMCW) signal, is used, such as a sawtoothwave, or a triangular wave.

The radar system 20 includes a transmit module with a transmit antenna,in which the transmit module is identified as Tx. The radar system 20also includes a receive module with a receive antenna, in which thereceive module is identified as Rx. The transmit and receive modules maybe configured in a single module or distributed among multiple modules.In some implementations, portions of the transmit and receive chainswithin the transmit and receive modules, respectively, are shared. Insome implementations, the transmit and receive antennas are separateportions of a similar antenna, such as subarrays within an array ofradiating elements. The transmit antenna transmits a radiating signal ata transmit angle, in which the transmitted radiating signal has a mainlobe and side lobes. Each side lobe of the transmitted radiated signalmay have a corresponding directional angle measured from a boresightposition as a reference.

The radar system 20 may transmit beams in a variety of directions, asillustrated. The transmitted beams are reflected from objects, whereinthe reflections are received at different times. Direct reflections froma target object, such as from vehicle 150, are identified by solidlines. Other reflections bounce off a first point toward a second point,such as to the target vehicle 150. Each of these incurs additional timefor return of the reflection to the radar system 20. Using these timerelationships, the present disclosures enable non-line of sight objectdetection using the environmental information. The environment of FIG. 1is provided for clarity of understanding, and additional environmentswill be provided herein.

FIG. 2 illustrates the relationships between the various objects, wherea first path from vehicle 110 deflects off object 120 to a target object(e.g., the vehicle 150) from which the signal is reflected and returnsto vehicle 110 by the same path. A second path deflects off object 130and a third path deflects off object 140. As the vehicle 150 continuesto travel towards vehicle 110, signals from the stationary environmentalobjects assist in tracking location and velocity.

The time for the signal to travel on a given path is indicated withsubscript representing (path, section), or (i,j). The signal times foreach path are then compared to the direct path from the radar system 20to the target object (e.g., the vehicle 150).

As given, the transmission time from the radar system 20 to the targetobject (e.g., the vehicle 150) is t_(target), and the roundtrip time is2*t_(target). The various times for the signal to traverse each path isdifferent than the time to the target object, in which the measure oftime is given for each path segment as t_(ij) and the roundtrip time as2*(t_(ij1)+t_(ij2)).

FIGS. 3-5 illustrate the travel time of paths 1, 2 and 3 and the timingassociated therewith. As illustrated, in FIG. 3 , a first path fromvehicle 110 deflects off object 120 to a target object (e.g., thevehicle 150) from which the signal is reflected and returns to vehicle110 by the same path. The round trip time from radar system 20 to thefirst section of path 1, 2*t₁₁, is less than the round trip of thedirect path, t_(target), while the total path 1 round trip, 2*(t₁₁+t₁₂)is greater than either 2*t₁₁ or 2*t_(target). As illustrated, in FIG. 4, a second path deflects off object 130. The round trip time from radarsystem 20 to the first section of path 2, 2*t₂₁, is less than the roundtrip time of the direct path, t_(target), while the total path 2 roundtrip time, 2*(t₂₁+t₂₂) is greater than either 2*t₂₁ or 2*t_(target). Asillustrated, in FIG. 5 , a third path deflects off object 140. The roundtrip time from radar system 20 to the first section of path 3, 2*t₃, isless than the round trip time of the direct path, t_(target), while thetotal path 3 round trip time, 2*(t₃₁+t₃₂) is greater than either 2*t₃₁or 2*t_(target).

FIG. 6 illustrates a comparison of a sounding signal as received at theradar system 20 from each of the three paths. The different pathsillustrated show the impact of the various obstacles in the path of thevehicle. The present disclosure enables the vehicle to distinguishstationary and mobile objects in real-time reducing the processing timerequired and improving responsiveness of the sensor fusion. Such time iscritical in driver assist functions, such as an Advanced DriverAssistance System (ADAS) or autonomous vehicle control, as the vehiclecontrol must respond in time to avoid collision, damage or otherunexpected situations.

FIG. 7 illustrates a process 200 for operating a radar system, accordingto various implementations of the subject technology. The process 200incorporates a sounding signal to identify stationary and mobileobjects. For explanatory purposes, the example process 200 is primarilydescribed herein with reference to the radar system 20 of FIG. 1 ;however, the example process 200 is not limited to the radar system 20of FIG. 1 , and the example process 200 can be performed by one or moreother components of the radar system 20 of FIG. 1 . Further forexplanatory purposes, the blocks of the example process 200 aredescribed herein as occurring in series, or linearly. However, multipleblocks of the example process 200 can occur in parallel. In addition,the blocks of the example process 200 can be performed in a differentorder than the order shown and/or one or more of the blocks of theexample process 200 may not be performed.

The process 200 begins at step 202, where the radar system 20 transmitsa sounding signal. Next, at step 204, the radar system 20 receivesreflections from an object. For example, the reflections may representreturning signals that are a delayed version of the transmitted soundingsignal. At step 204, the radar system 20 determines whether the receivedreflections are a target path reflection or another type of reflection.If the reflections are along the target path, process 200 proceeds tostep 206 where the target information is stored and used to determinethe target location and velocity. Otherwise, the process proceeds tostep 208. In some aspects, the target path is the direct path of thevehicle, which may not be a straight line, but is meant to consider theplanned path of the vehicle.

If an object is within the direct path, there is a need to take animmediate action, even if that action is not to change course. In thisrespect, the process 200 proceeds to step 214 from step 206, where thetarget information is provided to a main controller, which interfaceswith a sensor fusion or other main controller in the vehicle.

Where the reflections are from other directions, the process 200proceeds to step 208, where processing continues to store the reflectioninformation from at least one set of reflections. The set of reflectionsoccurs such as illustrated by paths 1, 2 and 3 of FIG. 1 , as the signalfirst reflects back to the radar system 20 from the object, such asobject 120, and then also is redirected to the target object 150, oranother object, and then returns to radar system 20 through the sameapproximate path. Therefore, for signals that intersect with the object120, there are two reflection times, 2*t₁ and 2*(t₁₁+t₁₂). This timedifference is used to determine a distance and reference locationbetween the object 120 and the target object 150.

Subsequently, at step 210, the reflection set information is stored andcompared to the target path reflection to generate comparisoninformation. Next, at step 212, the radar system 20 determines alocation of at least one object as a function of the comparisoninformation. Subsequently, at step 214, this information is thenreported to the main controller. In this way, the sounding signal isused to build a landscape for the vehicle in real time. As the vehiclemoves forward, the stationary positions are known and may be consideredas known, static entities.

FIG. 8 illustrates another situation 220, in a city street having atarget vehicle with a radar system (not shown). The vehicle 212 hasseveral direct paths to other moving vehicles, identified by the solidlines. The vehicle 212 also a has direct path to several stationaryobjects, in this situation 220 these are buildings 224. The transmissionsignal is reflected from the buildings 224 to identify other movingvehicles around the corner from the vehicle 212. By incorporating thereflection information, such as from an FMCW signal, the vehicle 212 candistinguish the buildings 224 from moving vehicle 226 and is also ableto identify a parked vehicle 228. The reflection information providesthis information for temporarily stationary objects as well. Rather thanrelying on GPS for every calculation and decision, the presentdisclosure provides a method to use the sounding signal to create a realtime landscape of an environment.

This is further illustrated in FIG. 9 , wherein the vehicle 212 hasradar system 240 for transmission of signals and object detection. Thetarget path is indicated by the solid line to vehicle 222. There areother objects 226, 228. As the transmission beams are reflected from thebuilding(s) 224, they create path 1 and path 2. The distance from thebuildings(s) 224 to the objects 226, 228 creates differences in thereflection information to enable location determination. The responsesof the sounding signal for path 1 and path 2 are illustrated withrespect to the target reflections. As indicated, the target path takesthe shortest amount of time for a roundtrip signal, and as the vehicles212, 222 separate further the time increases. If the distance betweenthe vehicles 212, 222 decreases, the time between target responses willdecrease proportionally. The same timing changes happen with respect tothe vehicle 212 and the building 224.

FIG. 10 illustrates a process 370 for developing an environmentallandscape of an environment, such as in real time. For explanatorypurposes, the example process 370 is primarily described herein withreference to the radar system 20 of FIG. 1 ; however, the exampleprocess 370 is not limited to the radar system 20 of FIG. 1 , and theexample process 370 can be performed by one or more other components ofthe radar system 20 of FIG. 1 . Further for explanatory purposes, theblocks of the example process 370 are described herein as occurring inseries, or linearly. However, multiple blocks of the example process 370can occur in parallel. In addition, the blocks of the example process370 can be performed in a different order than the order shown and/orone or more of the blocks of the example process 370 may not beperformed.

The process 370 begins at step 372, where the radar system 20 receiveselectromagnetic radiation, such as a reflection signal, from an objecthaving zero velocity. Next, at step 374, the radar system 20 determineswhether there are other reflections from the object. If there are otherreflections from the object, the process 370 proceeds back to step 372to process these reflections to form a set of reflections. Otherwise,the process 370 proceeds to step 376. At step 376, the radar system 20determines whether the set of reflections indicates a stationary object.If the set of reflections indicate a stationary object, then the process370 proceeds to step 380. Otherwise, the process 370 proceeds to step378. In some implementations, the process 370 may optionally determineif the detected object is a mobile object that is not in motion, or ifthe detected object is a permanent stationary object based on thereflection set. At step 378, the object information is stored to track amoving target object. At step 380, the location of the stationary objectis stored and the stored information is compiled to form anenvironmental landscape profile. Subsequently, at step 382, thelandscape profile from step 380, as well as the tracking informationfrom step 378, may be reported to a main controller, such as an antennacontroller, system controller, sensor fusion and so forth.

FIG. 11 illustrates a transceiver module, according to variousimplementations of the subject technology. A transceiver 400 adapted forradar operation, such as radar system 20. The transceiver 400 includesantennas 430 having beam control unit 418 for beam forming 442 and beamsteering 444. A sounding signal control unit 420 is coupled to antennas430. The information is processed to create an environment profile, 422.In operation, the antennas 430 are coupled to modulation control 440 andobject detection module 416 having a doppler process unit 417 to extractreflection information from modulated signals. The transceiver 400 alsoincludes a memory storage unit 408 for storing both volatile andinvolatile memory data. A processing unit 404 controls an informationmanagement unit 406 and control interface 402 for communication withother system controls, such as a sensor fusion in a vehicle.Communication within the transceiver 400 may be transmitted over bus410. The antennas 430 are configured to scan an environment around avehicle, in which reflected signals provide indications of positions andvelocity, as well as other characteristics of objects. This creates aradar system for enabling the vehicle to understand its surroundings.The sounding signal is added to such a system to provide additionalinformation and assist the vehicle system to create a real timelandscape. There is further an object recognition unit 424 that receivesthe analog data from the antennas and/or the processed data of location,velocity and so forth, and determines an object type therefrom. In someimplementations, the object recognition unit 424 includes a neuralnetwork (NN) processor, such as a convolutional NN (CNN) that trains onknown data to match received data to images or object types. In someimplementations, the object detection module 416 and the objectrecognition module 424 may be integrated in a perception module. TheDoppler process unit 417 uses the received reflection from an object ortarget to determine a location, velocity and other parameters of theobject. This may be done by use of an FMCW signal having a sawtooth,triangular or other wave form, as illustrated in FIG. 11 .

FIG. 12 illustrates an antenna 430 within the transceiver module 400 ofFIG. 11 , according to various implementations of the subjecttechnology. The radar system 20 of FIG. 1 works in collaboration withradiating elements in the antenna 430. As illustrated in FIG. 11 , theantenna 430 includes a power distribution and division portion 450, asuper element antenna array portion 452, a radiating portion 454 and RFcontroller 456. Not all of the depicted components may be used, however,and one or more implementations may include additional components notshown in the figure. Variations in the arrangement and type of thecomponents may be made without departing from the scope of the claimsset forth herein. Additional components, different components, or fewercomponents may be provided.

The illustrated example of the antenna 430 is not meant to be limiting,but rather to provide a full example of the application of the presentdisclosure. The present disclosure describes the flexibility and robustdesign of the subject technology in antenna and radar design. Theconcepts described herein are also applicable to other systems and otherantenna structures. The disclosure presented herein, along withvariations thereof, may be used in communication systems or otherapplications that incorporate radiating elements and feed structures.

The super element antenna array portion 452 provides transmission pathsfor propagation of transmission signals.

The RF controller 456 includes phase shifting elements and controlcircuitry for beam formation and beam-steering. The radiating portionmay be an array of radiating elements, such as metamaterial elements.The RF controller 456 can control the generation and reception ofelectromagnetic radiation, or energy beams. The RF controller 456determines the direction, power and other parameters of the beams andcontrols the antenna 430 to achieve beam steering in various directions.In some implementations, the RF controller 456 determines one or moreportions of a radiation pattern of radiating elements in the radiatingportion 454 in response to detection of an object, and determines adirectivity of a transmission from radiating elements in the radiatingportion 454 to increase gain of the transmission in a direction of theobject based on the one or more portions of the radiation pattern. Insome aspects, the one or more portions of the radiation pattern includesa first portion of the radiation pattern that corresponds to a mainlobe, a second portion of the radiation pattern that corresponds to atleast one side lobe and a third portion of the radiation pattern thatcorresponds to an overlapping area of the main lobe and the at least oneside lobe. The antenna 430 also includes modules for control ofreactance, phase and signal strength in a transmission line.

The present disclosure is described with respect to a radar system,where the antenna 430 is a structure having a feed structure, such asthe power distribution and division portion 450, with an array oftransmission lines feeding a radiating array, such as the radiatingportion 454, through the super element antenna array portion 452. Insome implementations, the super element antenna array portion 452includes a plurality of transmission lines configured withdiscontinuities within the conductive material and the radiating portion454 is a lattice structure of unit cell radiating elements proximate thetransmission lines. The power distribution and division portion 450 mayinclude a coupling module for providing an input signal to thetransmission lines, or a portion of the transmission lines. In someimplementations, the coupling module is a power divider circuit thatdivides the input signal among the plurality of transmission lines, inwhich the power may be distributed equally among the N transmissionlines or may be distributed according to another scheme, such that the Ntransmission lines do not all receive a same signal strength.

In one or more implementations, the power distribution and divisionportion 450 incorporates a dielectric substrate to form a transmissionpath, such as a SIW. In this respect, the power distribution anddivision portion 450 may provide reactance control through integrationwith the transmission line, such as by insertion of a microstrip orstrip line portion that couples to a reactance control mechanism (notshown). The power distribution and division portion 450 may enablecontrol of the reactance of a fixed geometric transmission line. In someimplementations, one or more reactance control mechanisms may be placedwithin a transmission line. Similarly, the reactance control mechanismsmay be placed within multiple transmission lines to achieve a desiredresult. The reactance control mechanisms may have individual controls ormay have a common control. In some implementations, a modification to afirst reactance control mechanism is a function of a modification to asecond reactance control mechanism.

In some implementations, the power distribution and division portion 450may include the power divider circuit and a control circuit therefor.The control circuit includes the reactance control mechanisms, orreactance controller, such as a variable capacitor, to change thereactance of a transmission circuit and thereby control thecharacteristics of the signal propagating through the transmission line.The reactance control mechanisms can act to change the phase of a signalradiated through individual antenna elements of the radiating portion454. Where there is such an interruption in the transmission line, atransition is made to maintain signal flow in the same direction.Similarly, the reactance control mechanisms may utilize a controlsignal, such as a Direct Current (DC) bias line or other control means,to enable the antenna 430 to control and adjust the reactance of thetransmission line. In some implementations, the power distribution anddivision portion 450 includes one or more structures that isolate thecontrol signal from the transmission signal. In the case of an antennatransmission structure, the reactance control mechanisms may serve asthe isolation structure to isolate DC control signal(s) from AlternatingCurrent (AC) transmission signals.

The transmission line may have various portions, in which a firstportion receives a transmission signal as an input, such as from acoaxial cable or other supply structure, and the transmission signaltraverses a substrate portion to divide the transmission signal througha corporate feed-style network resulting in multiple transmission linesthat feed multiple super elements. Each super element includes atransmission line having a plurality of slots. The transmission signalradiates through these slots in the super elements of the super elementantenna array portion 452 to the radiating portion 454, which includesan array of MTS elements positioned proximate the super elements. Insome implementations, the array of MTS elements is overlaid on the superelements, however, a variety of configurations may be implemented. Thesuper elements effectively feed the transmission signal to the array ofMTS elements, from which the transmission signal radiates. Control ofthe array of MTS elements results in a directed signal or beamform.

As described in the present disclosure, a reactance control mechanism isincorporated to adjust the effective reactance of a transmission lineand/or a radiating element fed by a transmission line. In someimplementations, the reactance control mechanism includes a varactorthat changes the phase of a signal. In other implementations, alternatecontrol mechanisms are used. The reactance control mechanism may be, orinclude at least a portion of, a varactor diode having a bias voltageapplied by a controller (not shown). The varactor diode may serve as avariable capacitor when a reverse bias voltage is applied. As usedherein, the term “reverse bias voltage” is also referred to herein as“reactance control voltage” or “varactor voltage.” The value of thereactance, which in this case is capacitance, is a function of thereverse bias voltage value. By changing the reactance control voltage,the capacitance of the varactor diode is changed over a given range ofvalues. Alternate implementations may use alternate methods for changingthe reactance, which may be electrically or mechanically controlled. Insome implementations, the varactor diode also may be placed betweenconductive areas of a radiating element. With respect to the radiatingelement, changes in varactor voltage produce changes in the effectivecapacitance of the radiating element. The change in effectivecapacitance changes the behavior of the radiating element and in thisway the varactor diode may be considered as a tuning element for theradiating elements in beam formation.

In some implementations, the radiating portion 454 is coupled to thesounding signal control unit 420 shown in FIG. 11 . Referring back toFIG. 11 , the sounding signal control unit 420 can generate the specifictransmission signal, such as a FMCW signal, which is used as for radarsensor applications as the transmitted signal is modulated in frequency,or phase. The FMCW transmitter signal enables the radar system 20 tomeasure range to an object by measuring the phase differences in phaseor frequency between the transmitted signal and the received signal, orreflected signal. Other modulation types may be incorporated accordingto the desired information and specifications of a system andapplication. Within FMCW formats, there are a variety of modulationpatterns that may be used within FMCW, including sinusoidal, triangular,sawtooth, rectangular and so forth, each having advantages and purposes.For example, sawtooth modulation may be used for large distances to atarget; a triangular modulation enables use of the Doppler frequency,and so forth. The received information is stored in the memory storageunit 408, in which the information structure may be determined by thetype of transmission and modulation pattern. Other modulation schemesmay be employed to achieve desired results. The sounding signal controlunit 420 may generate a cellular modulated signal, such as an OrthogonalFrequency Division Multiplexing (OFDM) signal. The transmission feedstructure may be used in a variety of systems. In some systems, thetransmission signal is provided to the antenna 430, and the soundingsignal control unit 420 may act as an interface, translator ormodulation controller, or otherwise as required for the transmissionsignal to propagate through a transmission line network of the powerdistribution and division portion 450.

Continuing with FIG. 12 , the antenna 430 includes the radiating portion454, composed of individual radiating elements discussed herein. Theradiating portion 454 may take a variety of forms and is designed tooperate in coordination with the super element antenna array portion452, in which individual radiating elements correspond to elementswithin the super element antenna array portion 452. As used herein, the“unit cell element” is referred to as an “MTS unit cell” or “MTSelement,” and these terms are used interchangeably throughout thepresent disclosure without departing from the scope of the subjecttechnology. The MTS unit cells include a variety of conductivestructures and patterns, such that a received transmission signal isradiated therefrom. The MTS unit cells may serve as an artificialmaterial, meaning a material that is not naturally occurring. Each MTSunit cell has some unique properties. These properties include anegative permittivity and permeability resulting in a negativerefractive index; these structures are commonly referred to asleft-handed materials (LHMs). The use of LHMs enables behavior notachieved in classical structures and materials. The MTS array is aperiodic arrangement of unit cells that are each smaller than thetransmission wavelength. In some implementations, each of the unit cellelements has a uniform size and shape; however, alternate and otherimplementations may incorporate different sizes, shapes, configurationsand array sizes.

As seen in the present disclosure, interesting effects may be observedin propagation of electromagnetic waves, or transmission signals. MTSelements can be used for several interesting devices in microwave andterahertz engineering such as antennas, sensors, matching networks, andreflectors, such as in telecommunications, automotive and vehicular,robotic, biomedical, satellite and other applications.

In some implementations, the power distribution and division portion 450includes a capacitance control mechanism controlled by the RF controller456 to control the phase of a transmission signal as it radiates fromradiating portion 454. In some implementations, the RF controller 456determines a voltage matrix to apply to the reactance control mechanismswithin the power distribution and division portion 450 to achieve agiven phase shift or other antenna parameters. In some implementations,the radiating portion 454 is adapted to transmit a directional beamwithout incorporating digital beam forming techniques, but ratherthrough active control of the reactance parameters of the individualunit cell elements that make up the radiating portion 454.

In a radar implementation, the RF controller 456 receives informationfrom within the antenna 430. Information may be provided from theantenna 430 to a sensor fusion module (not shown). This implementationdepicts a vehicular control system, but is applicable in other fieldsand applications as well. In a vehicular control system, the sensorfusion module can receive information (digital and/or analog form) frommultiple sensors and can interpret that information, making variousinferences and initiating actions accordingly. One such action is toprovide information to the RF controller 456, in which that informationmay be the sensor information or may be an instruction to respond tosensor information. The sensor information may provide details of anobject detected by one or more sensors, including the object's range,velocity, acceleration, and so forth. The sensor fusion module maydetect an object at a location and instruct the RF controller 456 tofocus a beam on that location. The RF controller 456 then responds bycontrolling the transmission beam through the reactance controlmechanisms and/or other control mechanisms for the antenna 430. Theinstruction from the RF controller 456 acts to control generation ofradiation beams, in which a radiation beam may be specified by antennaparameters such as beam width, transmit angle, transmit direction and soforth.

In some implementations, the signal is received by each unit cellelement of the radiating portion 454 and the phase of the radiatingportion 454 is adjusted by the RF controller 456. In someimplementations, transmission signals are received by a portion, orsubarray, of the radiating portion 454. The radiating portion 454 may beapplicable to many applications, including radar and cellular antennas.The subject technology considers an application in autonomous vehicles,such as an on-board sensor to detect objects in the environment of thevehicle. Alternate implementations may use the subject technology forwireless communications, medical equipment, sensing, monitoring, and soforth. Each application type incorporates designs and configurations ofthe elements, structures and modules described herein to accommodatetheir needs and goals.

In the antenna 430, a signal is specified by the RF controller 456,which may be in response to prior signals processed by an ArtificialIntelligence (AI) module that is communicably coupled to the antenna430. In other implementations, the signal may be based on programinformation from the memory storage unit 408. There are a variety ofconsiderations to determine the beam formation, in which thisinformation is provided to the RF controller 456 to configure thevarious unit cell elements 408 of the radiating portion 454.

When the transmission signal is provided to the antenna 430, such asthrough a coaxial cable or other connector, the transmission signalpropagates through the power distribution and division portion 450 tothe super element antenna array portion 452 through which thetransmission signal radiates to the radiating portion 454 fortransmission through the air. As depicted in FIG. 12 , the super elementantenna array portion 452 and the radiating portion 454 are arrangedside-by-side, however, the physical arrangement of the radiating portion454 relative to the super element antenna array portion 452 may bedifferent depending on implementation.

The implementation illustrated in FIG. 12 enables phase shifting ofradiating signals from radiating portion 454. This enables a radar unitto scan a large area with the radiating portion 454. For vehicleapplications, sensors seek to scan the entire environment of thevehicle. These then may enable the vehicle to operate autonomously, ormay provide driver assist functionality, including warnings andindicators to the driver, and controls to the vehicle. The subjecttechnology in the present disclosure is a dramatic contrast to thetraditional complex systems incorporating multiple antennas controlledby digital beam forming. The subject technology increases the speed andflexibility of conventional systems, while reducing the footprint andexpanding performance.

It is also appreciated that the previous description of the disclosedexamples is provided to enable any person skilled in the art to make oruse the present disclosure. Various modifications to these examples willbe readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other examples withoutdeparting from the spirit or scope of the disclosure. Thus, the presentdisclosure is not intended to be limited to the examples shown hereinbut is to be accorded the widest scope consistent with the principlesand novel features disclosed herein.

As used herein, the phrase “at least one of” preceding a series ofitems, with the terms “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item).The phrase “at least one of” does not require selection of atleast one item; rather, the phrase allows a meaning that includes atleast one of any one of the items, and/or at least one of anycombination of the items, and/or at least one of each of the items. Byway of example, the phrases “at least one of A, B, and C” or “at leastone of A, B, or C” each refer to only A, only B, or only C; anycombination of A, B, and C; and/or at least one of each of A, B, and C.

Furthermore, to the extent that the term “include,” “have,” or the likeis used in the description or the claims, such term is intended to beinclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.” Theterm “some” refers to one or more. Underlined and/or italicized headingsand subheadings are used for convenience only, do not limit the subjecttechnology, and are not referred to in connection with theinterpretation of the description of the subject technology. Allstructural and functional equivalents to the elements of the variousconfigurations described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and intended to beencompassed by the subject technology. Moreover, nothing disclosedherein is intended to be dedicated to the public regardless of whethersuch disclosure is explicitly recited in the above description.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of what may be claimed, but ratheras descriptions of particular implementations of the subject matter.Certain features that are described in this specification in the contextof separate implementations can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple implementations separately or in any suitable sub combination.Moreover, although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to a subcombination or variation of a sub combination.

The subject matter of this specification has been described in terms ofparticular aspects, but other aspects can be implemented and are withinthe scope of the following claims. For example, while operations aredepicted in the drawings in a particular order, this should not beunderstood as requiring that such operations be performed in theparticular order shown or in sequential order, or that all illustratedoperations be performed, to achieve desirable results. The actionsrecited in the claims can be performed in a different order and stillachieve desirable results. As one example, the processes depicted in theaccompanying figures do not necessarily require the particular ordershown, or sequential order, to achieve desirable results. Moreover, theseparation of various system components in the aspects described aboveshould not be understood as requiring such separation in all aspects,and it should be understood that the described program components andsystems can generally be integrated together in a single hardwareproduct or packaged into multiple hardware products. Other variationsare within the scope of the following claim.

What is claimed is:
 1. A sounding signal system, comprising: an antennaconfigured to transmit a sounding signal into an environment; and anantenna controller coupled to the antenna and configured to: controlbeam forming and beam steering of the antenna for a determineddirection; initiate transmission of the sounding signal in thedetermined direction; detect a first reflection of the sounding signalfrom a first reflection point in the environment; determine a locationof the first reflection point from the reflection of the sounding signalat a first time; determine the first reflection point is within a directline of sight from the antenna; detect a second reflection of thesounding signal from a second reflection point at a second time afterthe first time; determine the second reflection point is not within thedirect line of sight from the antenna; store the first and secondreflections as a reflection set associated with the sounding signaltransmitted at a first transmission time; and determine a location of atleast one object as a function of comparing multiple reflection sets. 2.The sounding signal system of claim 1, wherein the first reflectionpoint deflects the sounding signal to the second reflection point. 3.The sounding signal system of claim 1, further comprising identifying astationary object as having a zero velocity value.
 4. The soundingsignal system of claim 3, further comprising storing information of aplurality of reflection sets in memory.
 5. The sounding signal system ofclaim 4, further comparing the information of the plurality ofreflection sets to track detected objects.
 6. The sounding signal systemof claim 5, further comprising creating a real time landscape of theenvironment.
 7. The sounding signal system of claim 1, wherein thesounding signal system is part of a vehicular control system and thesounding signal is transmitted from a radar module.
 8. The soundingsignal system of claim 1, wherein the environmental landscape profileidentifies a location of a stationary object in an environment.
 9. Thesounding signal system of claim 1, further comprising: receiving analogdata from the antenna; performing object recognition from the analogdata, the object recognition including identification of the location,velocity or type of object detected.
 10. A method for a sounding signal,comprising: configuring an antenna to transmit a sounding signal into anenvironment; controlling beam forming and beam steering of the antennafor a determined direction; transmitting the sounding signal in thedetermined direction; detecting a first reflection of the soundingsignal from a first reflection point in the environment; determining alocation of the first reflection point from the reflection of thesounding signal at a first time; determining the first reflection pointis within a direct line of sight from the antenna; detecting a secondreflection of the sounding signal from a second reflection point at asecond time after the first time; determining the second reflectionpoint is not within the direct line of sight from the antenna; storingthe first and second reflections as a reflection set associated with thesounding signal transmitted at a first transmission time; anddetermining a location of at least one object as a function of comparingmultiple reflection sets.
 11. The method of claim 10, further comprisingdistinguishing between a plurality of objects, and wherein the soundingsignal is a frequency modulated continuous wave signal.
 12. The methodof claim 11, wherein the set of reflections from the plurality ofobjects have approximately a same angle of arrival, and wherein themethod further comprises compiling individual reflection times from theset of reflections.
 13. The method of claim 12, wherein the soundingsignal has a boresight direction of a main reference beam and side lobebeams having angles having angular directions with respect to theboresight direction, wherein the boresight is the line of sight to afirst object and the angles are directed at other objects in theenvironment.
 14. The method of claim 13, wherein at least one object isin a non-line of sight area.
 15. The method of claim 14, furthercomprising scanning the sounding signal over an angular range based atleast on different phase shifts applied to the reference signal.
 16. Themethod of claim 15, wherein the sounding signal is transmitted from avehicle and the method further comprises: identifying a path of thevehicle; and identifying one or more other objects in the path of thevehicle as a moving target object or a stationary target object.
 17. Themethod of claim 16, further comprising: generating a landscape layout ofthe vehicle to the first object based on the set of reflections; andidentifying objects in a path of the vehicle from the landscape layout.18. The method of claim 17, wherein the landscape layout is generated inreal time.
 19. A processing system, comprising: a memory storage unit;and at least one processing unit configured to: control beam forming andbeam steering of the antenna for a determined direction; initiatetransmission of the sounding signal in the determined direction; detecta first reflection of the sounding signal from a first reflection pointin the environment; determine a location of the first reflection pointfrom the reflection of the sounding signal at a first time; determinethe first reflection point is within a direct line of sight from theantenna; detect a second reflection of the sounding signal from a secondreflection point at a second time after the first time; determine thesecond reflection point is not within the direct line of sight from theantenna; store the first and second reflections as a reflection setassociated with the sounding signal transmitted at a first transmissiontime; and determine a location of at least one object as a function ofcomparing multiple reflection sets.
 20. The processing system of claim19, wherein the sounding signal comprises a frequency modulatedcontinuous wave signal.